The Chief Inspector of Mines has issued guidelines to assist employers in preventing flammable gas explosions and following best practice in lamp room checks and in multi-blasting operations
On 9 April 2021, the Chief Inspector of Mines (CIoM) issued various guidelines applicable to mining employers. We summarise below the key aspects of these guidelines.
Guideline for the compilation of a mandatory code of practice for the prevention of flammable gas explosions in mines other than coal mines
The CIoM published new guidelines for employers to compile a mandatory Code of Practice (COP) to prevent flammable gas and coal dust explosions at mines. It is important to note that these guidelines do not apply to coal mines / collieries. The effective date is 1 May 2021.
Flammable gas may be present in the strata at all mines. The erratic occurrences of flammable gas lead to a tendency to underestimate the potential dangers associated with the liberation of flammable gasses into the workings of a mine. In recent years, this has caused an increase in fatalities attributed to flammable gas explosions.
The guidelines aim to assist employers to compline a COP which, if properly implemented, will considerably reduce the risk of an ignition of flammable gas.
The guidelines stipulate that the COP must at least cover certain aspects, including:
| Identification of flammable gas sources, occurrences and composition | | Control of gas emissions | | Detection of flammable gas | | Reporting of flammable gas |
| Dilution, removal and dispersion of flammable gas | | Development ends and accessible tunnels | | Stopes | | Stoped working spaces |
| Clearing of flammable gas | | Ventilation controls | | Classification of hazardous areas | | Controls of ignition sources |
The employer must also prepare an implementation plan for the COP that covers issues such as organisational structures, roles and responsibilities and a schedule for the COP that will enable proper implementation.
As part of the mandatory COP guidelines on flammable gases, the CIoM also includes two further guidance notes as annexures that deal with lamp room practice and multi-blasting operations. We include a summary of these annexures below.
Guidance note for lamp room practice
This guidance note was published to assist employers in ensuring their detection instrumentation, self-contained self-rescuers and portable lamps are in proper working condition at the beginning of each shift.
Employers are encouraged to prepare a COP on lamp room practice, for which they should use the guidance note as a point of reference.
The guidance note deals with several issues relating to lamp room practice, including:
- the appointment of a competent person
- certification of specification compliance
- allocation of equipment in compliance with SABS specifications
- storage of equipment
- equipment control
- reporting
- compliance tests
Guidance note for multi-blasting operations
This guidance note was issued because a recent mine disaster highlighted the urgent need to review blasting and ventilation arrangements. The risk of flammable gas explosions in underground metalliferous mines has also increased.
The guidelines are designed to assist mines with the calculation of re-entry periods for the different types of multi-blasting.
The guidelines distinguish between different types of blasting:
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Time-blasting | Blasting operations taking place not more than once in any 24-hour cycle |
|
Multi-blasting | Multiple blasting, inclusing shaft sinking operations which could take place during any working shift |
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Flexi-time blasting | Blasting more than once in 24 hours, but not more than once per shift for both stoping and development, taking cognisance of a sufficient re-entry period to clear all airways where people are expected to work or travel |
In terms of Regulation 9.2(1) under the Mine Health and Safety Act 29 of 1996, the employer must ensure that employees’ occupational exposure to health hazards is maintained below certain limits (set out in a separate schedule). The guidelines set out four different re-entry intervals, which must expire before people can re-enter the workings of a mine in which blasting has taken place:
| Nil re-entry interval | | General re-entry interval | | Multi-blast re-entry interval | | Fixed-time multi-blast re-entry interval |
The guidelines also require employers to conduct a risk assessment at the specified operation. Appropriate exposure measurements and environmental engineering controls must be in place to comply with legal occupational hygiene requirements. The employer should take the following hazards into account when conducting a risk assessment:
- Noxious fumes from blasting
- Dust created by blasting
- Flammable gas
- Thermal environment
- Diesel emission.
